i feel like a bad person

so my boyfriends brothers girl is having a baby and im so upset about it and it makes me want to cry when anyone brings it up or i see her walking around with her baby belly 😢 and the baby is almost here. see i miscarried 3 years ago and have been ttc on and off for about 2 years just really started trying again 4 months ago and nothing has happened yet 😡 its just so unfair and i dont understand it i find myself getting more and more depressed about it and im starting to lose hope.